Long and short span construction



Aug. 20, 1940. L. DAVIDSON LONG AND SHORT SPAN CONSTRUCTION 3 Sheets-Sheet 1 NVENTOR Filed Nov. 15, 1937 BY I I Fig 2.

, 1/ I a I z ATTORNEYS Aug. 20, 1940. DAVIDSON LONG AND SHORT SPAN CONSTRUCTION Filed Nov. 15, 1937 3 Sheets-Sheet 2 INVENTOR I M MIL/71 1.

BY 5, 417, W-ewrD ATTORNEYS Filed Nov. 15, 1937 5 Sheets-Sheet '3 INVENTOR.

BY 1/ v MW, '5 I A TTORNEYS.

Patented Aug. 20, 1940 UNITED STATES LONG AND SHORT SPAN CONSTRUCTION Louis Davidson, Hewlett, N. ,Application November 15, 1937, Serial No. 174,513

2'1 Claims. (01. 1085-1) This invention pertains to improvements in building structures for various buildings, bridges, and the like whereinit is desired to have long span constructions, whether the structures be long span arches or long span rigid frames..-

The improved construction meets recent demands in the construction field, i. e., to give unobstructed space from floor toceiling, especially at the sides near the top of the side portions of the main arches, and to 'give a wide, unobstructed space/from wall to wall, and to give stiffer resistance and less horizontal movement at the walls of the building when the frame is under heavy loading, or under strains from temperature variations. Also, the invention permits the increase of span limits and general efficiency of integral I or H beams for use in long span building constructions, and the like.

More particularly the invention relates to novel building constructions of the long span type that have greater strength and. longer span limits with small size cross-sections of I beams, concrete, etc., being built in a novel manner. The improved construction herein is attained at much less-cost while maintainingrthe desired safety and strength. I

Further, this invention relates to improved long span arch construction for buildings, bridges or the like, and includes important features in the construction of the arches themselves and in addition to partial arches that form one of the important features of the invention.

Heretofore, in providing buildingor bridge constructions, it has been common to provide a series of parallel arches and to have these arches connected together by cross pieces that engage the arches usually at right angles to thearches. These cross pieces act to give greater strength to the complete framework and to provide a support for the roof, but they do not relieve the arches themselves of any of the load. The invention herein includes means for relieving the main arches of part of the load. e

In the prior known arch structures, where there is a portion of the arch that is substantially vertical and then flattens off to form the top or roof portion, there is required at the juncture of the vertical and flat portions a very considerable reinforcement. That reinforcement is usually very large in size and takes up a great deal of room on the inside of the building where the room is needed. Heretofore this reinforcement has taken the form of a long curve extending from quite a distance down on the vertical portion of the arch to quite a distance along on to the top or relatively flat portion of the arch. These curved reinforcing structures are objectionablebecause they are usually very deep and extend downwardly quite a distance thereby reducing the head roomat the junctureof the side and top portionsof the main arch. building construction of this old type withthe long curvedreinforcements calls for a balcony or a pathway fastened to thevertical or side portion of the arch, then the balcony or pathway must necessarily be located lower, or the'height of the vertical portion of the arch must be increased to give head room due to the presence of the large deep. curved reinforcement. The additional height of the building in order to properly position the balcony or pathway adds to the difliculty of the loading strains and requires more structural material, and also adds extra wall height resultingin extra building height costing more to construct and maintain.

One of the features of this invention is to provide a novel frame construction in buildings of long span structures,.and in bridges and the like, so that maximum strength, and safety, and head room may be obtained at a minimum cost and without, sacrificing other benefits of this type of construction; v

Another feature of the invention is to provide a novel type of long span arch construction, and novel partial arches as forming the connecting means between the arches at or near the side portions thereof to thereby take part of the load and to obtain greater strength and greater safety, and allow the arches and connecting structures to be made of smaller size members or elements, or to be effective for longer or'higher spans, and to be made with more efficient reinforcing pieces when reinforcement is required. l

A further feature of the invention is to provide what will hereinafter be known as partial arches and preferably have them mounted between the main arches and extending upwardly, in most cases to substantially the same height as the vertical or side portions of the main arches,

.arch to carry its share of the stresses, and espe- When the cially the bending loads at the critical points which are usually where the vertical or side portions of the arch join the top or substantially fiat portion of the main arch.

This novel type of structure, in most instances,

eliminates the very large undesirable curve reinforcing means which has been required in the prior types of arches, and in some cases makes the curve reinforcements altogether unnecessary.

By this novel type of long span construction herein, it will be understood that the arches and partial arches and the connecting elements may be constructed of rolled I or H-beam sections, or combinations thereof, properly joined together, or may be built-up arches of the truss form, or solid web plate and angle flange type, or may be made of reinforced concrete, or a combination of these types.

Also, this type of long span arch construction provides for the so-called fiat top type of arch. The flat top portion of the arch is joined with the side portions at the ends of the top so that obtuse angles are formed on the inside of-the junctures. In each of the arches of the improved construction herein, it is to be noted that they are formed of substantially uniform depth along their lengths except at the junctures where the depths are increased to a very much smaller degree than heretofore as will be set forth in detail at a later point in the description.

When employing the rolled beam structures of I or H cross sections, it has been found that a very large saving has been made in the design, in the fabrication, and in the erection of the frame constructions.

In addition, one of the features of this invention permits the addition of relatively small connecting members to be desirably placed for reinforcing the general long span arch structure in order to carry any extra loads, which intermittently may be placed on a particular portion of the building or bridge. For instance, in the building there may be placed additional connecting or bracing elements or beams to give a greater factor of safety to resist wind loads or the like.

By employing this novel type of long spanarch construction described herein, it has been possible to reduce the total quantity of materials required, and also reduce the amount of fabrication, and reduce the cost of erecting the building, and also reduce the total over-all construction cost.

The improved building structure also permits longer and more rigid span arches that will have stiffer resistance and less horizontal movement at the vertical or side walls when the building is under heavy loads, such as from ice, snow or winolage, or loads created by expansion due to wide temperature ranges, or loads due to other causes.

This invention gives greater strength at the critical points thereby allowing longer span arches for buildings and bridges, and increases the present maximum effective clearances without resorting to a large number of reinforcements at places where not desired. In addition the invention allows for the reduction of wall heights without sacrificing interior vertical clearances at points near the walls. Further, this improved long span construction provides partialarches to carry their proportional share of the bending moments and thrust in the arches at the vertical or steep sides thereof, thereby obtaining reduction of the size of the members and adding to economy in fabrication and erection.

A preferred embodiment of this invention is illustrated in the accompanying drawings where- 1n:

Fig. 1 is a diagrammatic plan view of the long span arch construction for a building with roof sheathing omitted and with two partial arches joining each arch.

Fig. 1a is also a diagrammatic plan view as in Fig. 1, and showing only a single partial arch at the end of each main arch.

Fig. 2 is a partial cross section along the line 22 of Fig. 1, and drawn to a different scale.

Fig. 3 is a partial cross section of the invention in a modified form.

Fig. 4 is a partial cross sectional view of a modified form of one form of the invention.

Fig. 5 is an enlarged knee detail at the juncture of two portions of one of the main arches, and can also be used at the center of the top portion of the arch. This is also a detail for use on the partial arches, and on arches without vertical ends as shown in Fig. 8.

Fig. 5a is a partial sectional view taken on the line 511-511 of Fig. 5 showing in detail the main parts of a preferred structure at one of the junctures.

Fig. 6 is a diagrammatic view of another manner of designing the main arches and the partial arches and the manner of connecting them together.

Fig. '7 is a diagrammatic view of another type of reinforced long span arch construction in which the partial arch structure is in the same vertical plane that passes through the length of the main arch.

Fig. 8 illustrates an arch and partial arch structure with both of these structures positioned at an angle to the vertical; and

Fig. 9 is a diagrammatic view taken on the section line 9--9 of Fig. 8 but to a different scale, showing portions of the partial arches connected to the main arches.

Referring now to the drawings, attention is particularly called to Figs. 2, 3, 4, 7, and 8, in which part of the total lengths of the main arch constructions are shown. Each of these figures shows a particular form of the main arches which goes to make up a frame construction embodying this invention. The main arches of the building are composed of a top portion I, and two side portions, IA. The side portions may be substantially vertical as shown in Figs. 2, 4, and 7, but they are often positioned at angles to the vertical as shown in Fig. 8, and they may be used in a vertical and inclined combination as shown in Fig. 3.

One of the features of this invention is to provide partial arches 2 that will cooperate with the main arches in supporting the total load, and to design these partial arches so that, preferably, one of them is mounted between any two adjacent main arches. Usually a partial arch extends upwards from its base to the height of the side or vertical portion of the main arch and then extends and is connected to the adjacent main arch or arches in a suitable manner and preferably at an acute angle thereto. In the disclosure herein the partial arch is shown as connected to the main arch at a point beyond the vertical or side portion of the main arch, as is indicated at junctures I! and 20, see Figs. 2, 3, 4, 6 and 8. The bases of the partial arches may be of the same heights as the bases for the main arches, or may be above or below the ends of the main arches.

The advantages and purposes of the partial arches are to provide additional strength to the main long span arch construction so as to assist in resisting the stresses and to materially resist the tendency of the main arches to push out-' wardly due to heavy loading, such as by ice, or snow, or wind, or due to'the expansion and contraction, from relatively large variations in temperature, or from any other cause. The side thrusts are considerable when the main arches are relatively low, and in that case the partial arches are of especial value to receive part of the load strains and stresses from the main arches.

It is preferred that the lower portions of the partial arches shall be positioned at any suitable position between the two adjacent main arches, and extend upwardly in a parallel fashion to the side portions of the main arches. However, the invention is not so restricted to these designs, as may be noted by reference to Fig. 9, where the partial arches, 2A, are positioned at an angle to the main arch composed of portions I and IA. If desired the partial arches may be positioned midway between the main arches.

The value of the partial arches and the means of connecting the upper portions thereof to the main arches will be more readily understood by reference to Fig. 1 wherein the lines I extend across the figure representing the top portions of the main arches, and the side portions of the main arches are represented as being Vertical, as noted at IA. The lower portions of the partial arches are shown in Fig. 1 as being vertical and being located substantially midway between the two adjacent main arches and parallel thereto. The upper portion 2 of the partial arches are shown as connectingthe lower portions 2A to the main arches at different points along the main arches, as is indicated on the left-hand side of Fig. 1 where the lines 2 in the next to the top section engage the main arches I at points further from the vertical side portions IA than are the connections as shown in the next lower sec tion in the same figure, Where the upper portions 2 of the partial arch engage the main arches at points nearer to'the side portions of the main arches.

Referring to Fig. 1a, it will be noted that the upper portions of the partial arches are connected to only one of the adjacent main arches. In many instances sufficient reinforcing strength is obtained by employing only one upper portion 2 of the partial arches instead of two upper portions of the partial arch, as indicated in Fig. 1.

The upper portions of the partial arches may be connected to the top portion of the main arch at any suitable point intermediate one end of the top portion and the mid-point or center thereof. With this construction the partial arches assume their portions of the load and thereby allow small curvature or no curvature at the junctures of the side and top portions of the main arches instead of the large or fiat curves heretofore found-necessary in order to obtain the desired strength.

It will be noted in the construction shown in Fig. 1 that additional reinforcing pieces 4 are provided between the two main arches at the end of the building. These reinforcing pieces 4, in combination with members 2, make a horizontal wind truss giving increased strength to the building construction to safely resist wind or other pressures against the end of the building. Other types of wind reinforcing members between main arches may be employed, or in combination with members 2, in order to obtain desired strength and safety.

Referring now to Figs. 2 and 4, it will be noted that the side portions IA of the main arches are vertical, and the lower portions, 2A, of the partial arches are positioned in line with the side portions of the main arches, and the upper portions of the partial arches extend to the main arch portion I, and join the same at an acute angle at IT as will be noted by referring to Fig. 1.

Modifications of this type of positioning of the side portions IA of the main arch, and the lower portions 2A of the partial arches, may be made in any desired manner, such, for instance, as are indicated in Figs. 3, 6, and 8. In Fig. 3 it will be noted that theside portion IA of the main arch is composed of straight sections, three in number. In this instance they form angles with a vertical line, and the partial arches in such structures are formed with the lower portion 2A being substantially vertical and having the upper portion 2 extend to the main arch I at H.

The particular type of structure shown in Fig. 3 assists materially in making it very convenient, and very economical, to carry a balcony 5 and to locate the same by fastening it to the side sections IA of the main arches and to the lower portions 2A of the partial arches, thereby giving a very satisfactory two-p'oint-support while allowing the pathway or distribution aisle to be located between IA and 2A, Fig. 3, or between IA, 2A and exterior wall or support.

Referring now to'Fig. 8, it will be noted that both the side portion IA of the main arch, and the lower portion 2A of'the partial arch are both positioned at an angle to a vertical line. Thus, any type of modification may be made in the positions of the side portions of the main arches and the lower portions of the partial arches in order to obtaindesired strength and economy to increase the width of the building or the height, or a combination of both, while at the same time maintaining strength and safety.

As referred to above the lower portions 2A of the partial arches noted in Fig. 8 are positioned at angles to the main arches as indicated in Fig. 9, and only engaging one of the adjacent main arches. Modifications of this structure may readily be made in accordance with other modifications set forth herein, for instance, see Fig. 1

and Fig. 1a.

Referring again to Fig; 2 the dotted line I5 indicates the depth to' which a reinforcement must be made to a main arch when there are no partial arches employed. It will be noted that a depth of reinforcement down to the line I5 does not give proper head room for the runway on the balcony 5, as indicated in this figure.

In order to obtain the necessary head room with reinforcing structure, shown by the dotted lines I5, it becomes necessary to increase the height of the building. This requires greater strength of the top and side portions of the main arch as there are large increased strains with the same loadings and span due to'the increased height of the side portion. By this invention the reinforcing at the juncture of the side portion and the top portion of the main arches is reduced down to a point as indicated at I6, and sometimes are omitted entirely, thus there is gained a material-amount of head room with less height of frame structure, and the weight of framework is reduced, and the balcony 5 is positioned at the desired height, and additional'intermediate supports for the balcony are provided to substantially reduce the cost of constructing the balcony. It will be understood that the reduction of the curve to the line I6 may be varied by reason of the size and location of the partial arches. These partial arches may be small or may even be eliminated with the improved type of juncture herein provided.

In the main frame constructions for buildings and the like, as shown in the drawings herein, there is provided a series of conventional purlins or beams 3 to support the roof sheathing over the main and partial arches and to join the side walls 9 which are here shown as being vertical. It will be understood that these purlins or beams 3 may be partially cut away to be built into the main arches, as is indicated in the drawings by the bottom portions of the purlins being shown as below the top flanges of the beams forming the side and top portions of the main arches, or these beams can be set on top of the arches.

Many of the buildings formed of the frame construction herein set forth are particularly adapted for armories or for buildings in which athletic events may be most advantageously carried on, and for expositions, meetings, conventions, or the like. It is desired in buildings for these purposes that there shall be balconies 5 and these balconies are to be positioned at a satisfactory height so that temporary bleachers 6 or I may be added, as shown in Fig. 2. By this type of structure the space under the balcony is made useful.

Referring now to Fig. 3, it is desirable to em ploy stiffening or bracing beams 8 between the main arches and the partial arches as shown in Fig. 2, and between the partial arches as shown in Fig. 3. The balconies are provided with steps I l and are positioned by brackets I8 suitably fastened to the side portions IA of main arches and to lower portions 2A of the partial arches.

Suitable connecting tie rods I I engage the ends of the main arches, as shown. If desired, suitable tie rods may be employed to connect the bottom ends of the lower portions of the partial arches, or each partial arch may have a tie rod connecting it with one or more of the tie rods II which connect the ends of the main arches. In structures of this nature it is desirable to have the ends of the main arches and partial arches mounted on foundations I2, as indicated in Figs. 2, 3, and 8. In the type of structure shown in Fig. 3 it may be desirable in many instances, to connect the side portions of the main arches together below the juncture points of the partial arches with the main arch and such types of connecting means are shown at I3.

A modified type of means for connecting the partial arches with the main arches is indicated in diagrammatic form in Fig. 6 in which the partial arches are positioned relatively close to and parallel to the main arches and are connected to beams or girders I9 which connect the main arches. Such connections are preferably obtained by the employment of stiff connections 20 which also engage the main arches and the beams or girders I9.

In the type of frame constructions for buildings, bridges and the like, shown in Fig. '7, it will be noted that the lower portion 2A of the partial arch is in line and in the plane with the main arch and extends beyond the side portion IA of the main arch. This type of structure is provided with suitable bracing connections as indicated whenever such structure is desired to have greater strength than what is obtained by just the partial arch structures of the lower portion 2A and the upper portion 2. By employing a structure of this form it will be noted that a pathway to balcony 5 is provided between the side portion IA of the main arch and the lower portion 2A of the partial arch.

Referring now to Figs. 5 and 5a, the particular reinforcement I6 at the juncture of the side portion IA and the top portion I of the main arch, as Well as at the juncture at 2A and 2 of partial arches is indicated as being one form which is economical, practical and sound engineering without having the curve part extend too far down from the juncture. By this structure a material increase in head room is obtained without reducing the height of the main arch. In this type of reinforcing structure it is desirable, when rolled beams, such as H or I-beams are employed in making up the arch or rigid frame, to cut the lower flanges 22 of the joining ends of the beam I and IA back for a desired distance from the ends thereof and to bend these ends away from the webs and join them together, as indicated in Fig. 5-. From a practical and desirable point of view the flanges are cut from the webs at the junctures of the flanges and webs, as indicated at 2! which designates the lower edges of the webs. The meeting of the two flanges is specifically determined to give a required increased depth or cross-section from the top flanges of I and IA, or 2 and 2A, thereby giving the proper reinforcement strengths. For purposes of increasing the strength at this juncture any suitable means may be employed, such as plates 23 which are fastened to the webs of I and IA at suitable positions, and which in the structure herein extends down to the flanges 22 as bent in the curved position. Preferably these plates 23 are positioned near the bottom edges of the webs, as shown. When desired, plate 29 is inserted between the plates 23 and directly beneath the lower edges 2! of the webs as shown in Fig. 5a. This plate 29 provides a suitable spacing means between plates 23. Any suitable fastening means such as bolts or rivets may be inserted through the two plates 23 and the plate 29, to hold the plates together, or these three plates may be welded together at desirable spots. If desired, spacing washers, instead of plate 29, may be placed between the plates 23 at points where rivets or bolts go through or where welds are made. If it is desired to also reinforce the flanges, this is accomplished by employing one or more reinforcing pieces 24, Fig. 5a which, preferably, are angle irons, bent and affixecl to the bent flange plates and at the same time to have these angle irons engage the reinforcing plates 23, as shown, when desired, and to have angle irons engage the webs at any desired place. It is also desirable to have a stiffening angle or piece 26 extend from the upper flanges of I and IA to the flanges 22 as bent, or, if desired, to engage part of the angle 24. When desired to obtain additional strength a web connecting plate 25 is provided. Plates 23, angle iron 24, and stiffener 26 or any one of them may be omitted and instead open lattice work may be substituted. Preferably, plates 23, angles 24, and angles 26, should be used on both sides of the web as shown in section in Fig. 5a, thus using these units in pairs. In the event much of the juncture is welded, or well riveted, it may then be possible or advisable to omit one or more of the angles or plates. If welded, splice plate 28 and angles 24 may be omitted. Many other details, of conarch and bridge structures;

struction can be'use'd here-with the principal idea of cutting parts of the flange plate from the weband bending the flange plate to required depthand then securing-the bent plates in their new positions. r

The end of I beam 21 which correspondsto a type of stifiening element or beam between the portions IA of the main arches, or between adjacent main and partial arches, or as indicated in Fig. 3, that extends between two adjacent partial arches may be located at this point and assist in preventing buckling ofarches or rigid bents. Another reinforcing element is splice plate 28 shownat the bottom of the curve formed by the flanges 22. In the event other reinforce: ment is required for added strength, cover plates may be placed atthe flanges 22 as bent. If desired a splice plate 28a may be added at the top of the juncture as shown in Figs. 5 and 5a.

This improved type of small curve at the junc-. ture of beams at an angle to each'other may be employed at difierent positionson main arches and partial arches,'or on either. It is herein shown at the junctures of the top portion of the main arch with the side portion thereof, but it is to be understood that this type of structure may be employed at the very top in the center signed to'produce a cross section so that the unit stresses come within allowable limits.

In the foregoing description the designation of longspan arch is to be considered as including what is known as rigid frame construction, which is often employed in building long span The partial arches will be incorporated with the rigid frame construction in substantially the same manner as withthe other long span arches.

While the rolled, sections have been shown as I- beams or H beams, it will be understood. that in some structures angle irons may be employed and the, lowerpart or flange maybe out back to form the curved'parts which would correspond to flanges 22 as bent. f Itwill be understood that the rolled beams may be welded together, or bolted or riveted together,-

or the foregoing methods may be combined in forming a long spanarch. I v

a It will be understood'from the: foregoing description that this improved long span arch and rigid frame construction permits much longer spans of the main arches than has heretofore been possible, has improved curved reinforce: ment at the juncture of two members at an angle toeach other, and allows the cantilever mount: ing of a balcony to have more closely spaced supports. This permits the reduction ofrequired weight of the buildings and of the balconies, while at the same time allows the de-' sired unobstructed head room. It .will 'benoted' in connection with the balcony construction-, andbuilt up of solid web plates and flange angles, or.

built upof angles,etc., of open web truss-like construction, or of reinforced concrete or the like, permits smaller size main arches and partial arch'es, makes for more rigid construction,

and gives greatenhead'room at'thegjoints be tween thetopportions-and the side portions of thearches, and permits the whole structure to bet fabricated and erected at greatly reduced cost while obtaining the desired'strength and safety. It is also understood that integral as employed herein includes structures of I or H construction, of concrete, or of built up plate and angle cross sections.v It will be noted that the side portions of the arches may be made of several short length pieces of substantially uniformdepth or of one piece of substantially uniform depth,- and that these side portions may be positioned vertically, or at angles to the vertical.

It will be understood that various changes and modifications may be made in the structure herein shown, butsuch changes and modifications will be considered-as being Within the scope of this invention, as outlined in the following.

claims.

1. In a longv span construction for buildings, bridges or the like, aseries of main arches positioned substantially parallel, and a plurality of partial arches-each positioned between said main arches and extending upwardly to join at least one of the'adjacent main arches at a point along the main arch before reaching themid-point of said arch to assist the main arches in carrying the loads. i j

2.,In .av long span construction for buildings, bridges-or the like, a series of main arches posie tioned substantially parallel, and a plurality of partial arches each positionedibetween said mainarches and-extending-'upwardly to join both of the adjacent main arches at points along said;

bridges, or the like, a series of main arches and a plurality of partial arches each mounted be-- tween the main arches and extending upwardly to join both of said main arches at angles thereto and at points other than at mid-points theree of there-by assisting the main arches in carrying the loads, one of the joints forming an acute angle.

T1 4. In; a;long .;span construction'for buildings; bridges or the like, a series of main arches-positioned substantially parallel, anda plurality of partial arches eachof which is mounted between the main arches and. has a portion parallel to the mainarches, andthen extending to at least one of the adjacent main arches and joining the same at a point along said; main arch before reaching the mid-point of said arch to assist the main arch in carrying the loads.

. 5. In a .long span construction for buildings, bridges, or ;the like,;a series of main arches each of which'iscomposed ofside portions and a top. portion, and ,a'plurality ofpartial arches each ofwhich is mounted between. two, adjacent main} arches, oneof said partial arches extending upwardly and having. portions thereof joining both of said adjacent main arches at points along the top portions thereofbefore reaching the mid: points ;oic.$,aid arches. l

.6. In a long span construction for buildings, bridges, or the like, a series of main arches positioned substantially parallel each of which is composed of side portions and a top portion, and

a series of partial arches each of which is mounted" betweentwoadjacent main arches, each' of said partial archesv extending. upwardly and-joining:

both of said adjacent main arches at points along the top portion thereof and before reaching the mid-points of said arches, a part of one of said partial arches engaging one of the main arches at an acute angle.

7. In a long span arch construction, a main arch composed of side portions and a top portion, and a partial arch positioned adjacent said main arch and joined to said main arch at a point intermediate one end of the top portion and the mid-point thereof.

8. In a long span arch construction, a main arch composed of side portions and a top portion, a partial arch positioned adjacent to said main arch and connected thereto, said partial arch being composed of a lower portion and an upper portion, said lower portion being positioned adjacent the side portion of said main arch and extending substantially as high as the side portion of said main arch, said upper portion of the partial arch connecting the lower portion thereof and the top portion of the main arch at some point intermediate the end of the top portion of the main arch and its mid-point.

9. In a long span arch construction for buildings, bridges or the like, a series of main arches each of which is composed of side portions and a top portion, said arches being positioned substantially parallel, and a plurality of partial arches, each of which is composed of a lower portion and an upper portion, the lower portion being positioned between said main arches and the upper portion thereof joining the main arches at points intermediate the nearest side portion therof and the mid-points of said arches.

10. In a long span arch construction for buildings, bridges, or the like, a series of main arches each of which is composed of side portions and a top portion, said arches being positioned substantially parallel, and a plurality of partial arches, each of which is mounted between two main arches and joined to said main arches, each of the partial arches being composed of a lower portion and an upper portion, the lower portion of the partial arch extending upwardly in parallel relation to said main arches and the upper portion of the partial arch joined to one of the main arches at points other than the mid-points thereof.

11. In a long span arch construction for buildings, bridges or the like, a series of main arches each of which is composed of side portions and a top portion, said arches being positioned substantially parallel, and a plurality of partial arches, each of which is mounted between two main arches and joined to said main arches, each of the partial arches being composed of a lower portion and an upper portion, the lower portion being positioned midway between the adjacent main arches and extending upwardly, and the upper portion of the partial arch extending to join the adacent main arches at acute angles thereto at points other than the mid-points of said arches.

12. In a long span arch construction for buildings and the like, a series of main arches, each of said main arches being composed of side portions and a top portion, the side portions being positioned at a large angle to the floor of the building the juncture points between the side portions and the top portion being provided without reinforcements, a plurality of partial arches mounted in association with said main arches, each of said partial arches being between two adjacent main arches and extending upwardly for a distance and then extending to engage at least one of said adjacent main arches at a point along the top portion of said arch other than at the center of said main arch.

13. In a long span arch construction for buildings, a series of main arches, each of said arches being composed of side portions and a top portion, said arches being positioned substantially parallel, each of the side portions being positioned at an angle to a vertical line, a plurality of partial arches, each of which is mounted between two adjacent main arches and extending upwardly at a greater angle to a vertical line than the side portions of the main arches, each of said partial arches then being connected to one of the main arches at a point along the top portion thereof other than at its mid-point, thereby transferring part of the stresses from a main arch to the adjacent partial arch member.

14. In a long span arch construction for buildings, a plurality of main arches positioned substantially parallel, each arch being composed of side portions and a top portion, said side portions extending upwardly from the foundations substantially vertically, a plurality of partial arches each of which is mounted between two adjacent main arches, each of said partial arches being composed of a lower portion which extends upwardly in a vertical position and an upper portion which extends from the vertical portion to join the main arches at points along the top portions thereof other than at their mid-point.

15. In a building construction of I-beams or H-beams joined together to form an arch, said arch being composed of side portions and a top portion, reinforcements at the juncture of the side portions with the top portion, each of said reinforcements being composed of the lower flanges of the joining beams cut free from the webs of the beams for a predetermined distance back from the ends thereof and being bent to meet and form a general curve between the side portion and the top portion of said arch, said flanges being cut from said beams at the junctures of the webs with the flanges, and additional means connecting the bent flanges with said webs for increasing the strength at said junctures.

16. In a building construction of I-beams or H-beams joined together to form an arch, said arch being composed of side portions and a top portion, reinforcements at the junctures of the side portions with the top portion, each of said reinforcements being composed of the lower flanges of the joining beams out free from the webs of the beams for a predetermined distance back from the ends thereof, and being bent to meet and form a general curve between the side portions and the top portion of said arch, said flanges being cut from said beams at the junctures of the webs with the flanges, means connecting the bent flanges with said webs for increasing the strength of said juncture, and a curved angle reinforcement member positioned on and affixed to said flanges as curved.

17. In a building construction of I-beams or H-beams joined together to form an arch, said arch beng composed of side portions and a top portion, reinforcements at the junctures of the side portions with the top portion, each of said reinforcements being composed of the lower flanges of the joining beams out free from the webs of the beams for a predetermined distance back from the ends thereof, and being bent to meet and form a general curve between the side portion and the top portion of said arch, said flanges being cut from said beams at the junc: tures of the webs with the flanges, means connecting the bent flanges with said webs for increasing the strength of said junctures, and spliced plates connected on the top and bottom parts of said flanges as cut and bent.

18. A joint between two rolled beam sections joined together at an angle to each other, said joint comprising a curved part which is formed by partly cutting the lower flanges of said beams free from the webs thereof at the junctures of said webs and said flanges and bending said out flanges to positions for joining them together at a point below the webs of said beams, and means for connecting the flanges together when so bent.

19. A joint between two I--beam or H-beam sections joined together at an angle toeach other, said joint comprising a curved part which is formed by cutting the lower flanges of said beams free from the webs thereof at the junctures of said webs and said flanges, said flanges as cut from the webs being cut to predetermined lengths, and said flanges being bent to join each other to form a curve between said beam sections, the curvature of said flanges as so bent being partially dependent upon the required strength of saidjuncture, and reinforcing means joining the webs of said beams and theflanges as bent in their new positions.

20. In a building construction, the'combination of a main arch composed of two side portions main arch near said junctures and having their other ends supported separately from said main arch support, each of said arches thereby receiving a portion of the load strains.

21 In a building constructiomthe combination of a main arch composed of two side portions and a top portion, the juncture points between'said side portions and said top portion being points of maximum strains in said arch, and a partial arch joined to the top portion 'of said main arch near one of the juncture points, the other end of said partial arch extending to a support, said partial arch thereby relieving said main arch of some of the load strains at the point of maximum moment.

22. In a building construction the combination of a main arch composed of a series of relatively short H- or I-beams joined together with their longer axes forming angles to each other in the line of the arch, a plurality of said joints between said beams being reinforced by providing increased depths of the beams at the joined points, and partial arches located adjacent said main arch near the ends thereof and extending upwardly and being .joined to the main arch at points intermediate the end of the arch and the mid-point thereof, said partial arches receiving part of the load strains.

23. In a building construction the combination of an arch composed of a series of relatively short H- or I-beams joined together with their longer axes forming angles to each other in the line of the arch, a plurality of said jointsbetween said beams being reinforced by providing increased depths of the beams at the joined points. 24. A long span arch construction composed of side portions and a top portion, said portions having the top surfaces and the bottom surfaces 'sub-' stantially parallel to each other except at the juncture points of said side portions with the top portion and at those points the depths of said arch construction are increased, and a partial arch positioned adjacent each side portion and joined to said top portion to partially relieve said juncture and said side portion of some of the stresses.

25. In a long span arch construction composed of side portions and a top portion, said portions having the top surfaces and the bottom surfaces substantially parallel to each other except at the juncture points of said side portions with the top portion and at those points the depths of said arch construction are increased to resist tension and compression, said top and side portions being of integralcross section, said side portions being inclined from the vertical towards the center of the top surfaces and the bottom surfaces sub stantially parallel to each other except at the juncture points of said side portions with the top portion, and a partial arch positioned adjacent to one of said side portions and joined to said juncture of said top portion and side portion and being positioned in the same vertical plane as said top portion and said side portions.

27. In a long span arch construction, said arch being composed of a top portion and side portions of substantially uniform depth of integral cross section and making a general curve from end to end of arch, said sideportions being straight and inclined from the vertical toward the center of the arch and extending to the points of joining with said top portion where the depths are increased to resist tension and compression and where obtuse angles are formed on the inside of 7 

